This invention relates to an elastomeric mounting and in particular, although not exclusively, to a mounting intended normally to be loaded in compression and to resist subjecting the elastomeric material to tensile loading.
The invention relates additionally, but not exclusively, to an elastomeric mounting suitable for use in a vehicle suspension such as the suspension of an off-road truck to transmit compression and tensile forces between two relatively movable components, especially between an axle and the end of a bogie pivot beam.
One example of an elastomeric element normally loaded in compression and resistant to tensile loading of the elastomeric material is that described in the specification of U.S. Pat. No. 4,615,513. That comprises an elastomeric body located between and bonded to rigid end plates. The elastomeric body incorporates a plurality of parallel, spaced, flat metal rings to prevent circumferential outwards bulging of the elastomeric body when the end plates are pressed together. The end plates are also held together by means of a mechanical connecting means in the form of holders which extend into the rubber body from the central portion of the respective end plates, and secondly a link element linked to the holders.
In this construction the mechanical connecting means should provide a limitation to the maximum expansion of the elastomeric body, so as to prevent that body being subjected to tensile loading and a risk of tearing. In practice, when subjected to heavy duty use and the high shock loads experienced in use as part of the suspension of an off-road truck, it is found that the chain links and holders can deform and that the elastomeric material becomes torn.
One object of the present invention, but not the exclusive object, is to provide an improved elastomeric mounting in which there is a better ability to withstand shock tensile loading and/or resist subjecting the elastomeric material to tensile load.
In accordance with one aspect of the present invention an elastomeric mounting comprises two rigid end members maintained spaced apart by an intervening tubular body of elastomeric material which defines a central chamber, and a substantially inextensible connecting means arranged to extend through said central chamber to interconnect said end members and resist more than a predetermined separation of the end members, one of the rigid end members having a cavity member associated therewith and which lies within the axial length of the mounting between the end members to define a location cavity, said one of the rigid end members having a substantially planar axially outwardly facing contact surface, a location member positionable in said location cavity captively to engage an end region of the inextensible connecting means and transmit force to the cavity member when the connection means is loaded in tension, said contact surface of an end member being adapted in use to be secured to one of two members to be interconnected by the mounting and said one of two members serving to provide an abutment surface which prevents the location member displacing to a position at which it ceases to captively engage an end region of the inextensible connecting means.
The cavity member may be provided by a formation which is integral or otherwise directly associated with said one of the rigid end members. Alternatively it may be defined by a part of buffer means associated with said one of the rigid end members and arranged to act in series with the connecting means for the transmission of tensile load. The buffer means may be of a kind which incorporates any one or more of the features described in our co-pending UK patent application of even date and entitled xe2x80x9cElastomeric Mounting (B)xe2x80x9d.
The location member may, for example, be comprised by a chain half link, and may captively engage a chain link which provides at least a part of said substantially inextensible connecting means.
An elastomeric mounting the subject of the present invention may incorporate one or more other features such as are described in detail below, and also one or more of the features as disclosed more generally in any one or more of our co-pending UK patent applications of even date and entitled xe2x80x9cElastomeric Mounting (A)xe2x80x9d, xe2x80x9cElastomeric Mounting (B)xe2x80x9d and xe2x80x9cElastomeric Mounting (D)xe2x80x9d.